The installation of a tile roof involves a variety of technical challenges and problems not encountered during the installation of a traditional shingle roof. Traditional shingles are relatively thin and can be placed almost flat onto the roof decking in overlapping rows. In contrast, roofing tiles tend to be thicker and more rigid, and do not tend to lie as flat when overlapping one another. Thus, roofing tiles require special consideration and handling, particularly when installing the first course along the eaves.
In addition to flat-shaped tiles, modem roof tiles are made in a variety of sizes and shapes to complement different architectural styles. For example, a traditional S-shaped tile might be used for Spanish-style architecture, while a W-shaped tile might be used for a Mediterranean-style project. The multitude of shapes available today increases the complexity of the technical challenges and problems encountered when installing a tile roof.
The installation of roof tiles typically begins with the step of laying a first row or course of tiles along the eaves of a roof. While the edges of the upper courses of tile will rest upon the next lowest course, the lowermost edge of the first course of tile has no tile upon which to rest. Thus, the lowermost edge of the first course of tiles must be elevated above the roof decking to the desired angle or pitch for proper installation.
Various methods and devices have been used for elevating the lowermost edge of the first course of tile, but some of these methods and devices can create new problems both during and after installation. Such problems include improper or inaccurate tile pitch, lack of universal fit among tiles of different shapes and sizes, unattractive appearance, poor drainage, poor ventilation, inadequate structural support, poor resistance to wind and weather, and increased vulnerability to bird nesting and animal infiltration.
Adequate drainage and ventilation is critical to the proper installation of a tile roof. Drainage is critical because the accumulation of water behind and under the tiles can lead to serious and expensive problems such as standing water, ice dams in cold climates, wood rot, roof leakage, and structural failure. Ventilation is critical to reduce heat transfer through the attic space and into the occupied living space. Also, a tile roof creates an air space between the tile and the roof deck which acts as a thermal barrier. Creating a flow of air through this air space can help dissipate accumulated heat.
Bird nesting and animal infiltration represent a significant problem for various tile shapes having what is known as a high profile. The curvature of a high-profile tile such as the traditional S-shaped Spanish tile creates a large space beneath the tile, making the eaves and roof vulnerable to bird nesting and animal infiltration. Similarly, the curvature of lower-profile tiles such as the W-shaped Mediterranean tiles also create open spaces along the eaves which require closure.
The prior art closure devices have been plagued by problems such as poor ventilation and interference with water shedding. One such prior art configuration requires the installation of a new, tall fascia board along the eaves to support the lowermost edge of the first course of tile. The fascia board creates a water dam at the edge of the roof, so a metal flashing must be installed to allow water to flow over the board.
Another field method involves the pouring of a strip of mortar along the eaves, with weep holes drilled or formed through it to allow water drainage. Another method in use involves the installation of metal eaves closure strips, with additional flashing and drilled weep holes for drainage, such as the one disclosed in U.S. Pat. No. 4,418,505 issued to Thompson on Dec. 6, 1983. Although weep holes allow some water to escape, they offer little or no ventilation of the roof. Although these field methods and devices may have their own advantages, they illustrate the need for systems that provide improved drainage and ventilation in addition to providing closure and accurate tile pitch.
Thus, there remains a need for a method and apparatus for elevating the first course of tile that will permit water to flow safely off the roof and promote adequate ventilation, while assuring proper tile elevation and support, and adequate resistance to animal and environmental infiltration. Such a method and apparatus should accomplish these goals in a reliable, durable, attractive, low-maintenance, and cost-effective manner.